The vertebrae of the spine are arranged in a column with one vertebral body aligned on top of the next (at least when the spine is vertical). Between each vertebral body resides a spongy intervertebral disc that transmits forces between adjacent vertebral bodies and provides a cushion between the adjacent bodies. The disc provides support for spine flexion, extension, and lateral motions.
In some cases, intervertebral disc degeneration or other deformities (“diseased disc”) can cause back pain. Conventionally, surgeons treat diseased discs by surgically removing all or a portion of the diseased disc and inserting an implant in the space vacated by the diseased disc, which implant may be bone, PEEK material, or other biocompatible implants as are generally known in the art. The adjacent vertebral bodies are immobilized relative to one another and, eventually, the adjacent vertebral bodies grow into one solid piece of bone completing the fusion.
For example, a convention method to fuse vertebral bodies includes piercing the intervertebral disc annulus. The surgeon removes all or a part of the disc nucleus. Next the surgeon would implant a fusion implant, such as a milled bone piece, or the like through the incision in the disc annulus.
Typically, a fusion plate or the like immobilizes the adjacent vertebral bodies. Immobilizing the superior and inferior vertebral bodes with an implant prompts fusion between the superior and inferior bodies into one solid piece of bone.
As can be appreciated, in some cases for whatever reason, the fusion does not properly occur. These incomplete or partial fusions require the surgery to be re-performed, which is traumatic and risky for the patient, and a drain on otherwise limited resources. Thus, it would be desirous to provide methods and apparatuses to correct incomplete or partial fusions.